1. Field of the Invention
This invention relates generally to wireless mobile devices (e.g., mobile telephones such as cellular telephones, mobile data devices, etc.) More particularly, it relates to the distribution of intelligent roaming databases (IRDBs) including a list of available carriers to a roaming mobile device.
2. Background
Intelligent Roaming Databases (IRDB) and Preferred Roaming Lists (PRL) are sources of information contained in a mobile device (e.g., a cellular telephone) that tell the mobile which wireless carriers that the mobile should use for service. These IRDBs and PRLs are defined, e.g., in IS-136 TDMA cellular standards, and in IS-95 CDMA cellular standards. The xe2x80x9cIRDBxe2x80x9d terminology is used in the IS-136 TDMA standards, and xe2x80x9cPRLxe2x80x9d terminology is used in the IS-95 CDMA standards. The present description and drawings contained herein refer to both IRDBs and PRLs collectively as xe2x80x9cIRDBxe2x80x9d noting that these concepts apply not only to both TDMA and CDMA standards, but to mobile devices as a whole. Moreover, the principles of the present invention relate equally to GSM and future 3rd generation systems which will use carrier list update mechanisms.
Currently, the IRDB information contained in the mobile devices is transmitted by a system IRDB manager maintained by a service provider, and updates are dictated by the service provider as changes to the wireless network system dictate.
All mobile devices within the service provider network contain the same IRDB.
The service provider initiates if and when any IRDB update will occur, but when it occurs, all mobile devices in a wireless network (e.g., potentially millions of mobile devices for any one update) will receive the updated system IRDB. Thus, the trigger for updating the system IRDBs in each of the mobile devices is the occurrence of a revision to the system IRDB (e.g., a new carrier coming online somewhere in the system, a new partner arrangement with another wireless carrier in a roamed area, etc.) When an update is triggered, all mobile devices in a wireless network become queued for receipt of the common system IRDB.
Using a conventional system IRDB, whenever the system IRDB for a particular service provider is updated for almost any reason, all mobile devices serviced by that particular service provider must be sent an updated system IRDB even though the update doesn""t affect every mobile device. This is particularly true if the update relates to a change in wireless carrier service in an area never entered by a particular mobile device.
Typically, a mobile device becomes available for an IRDB update when powered on and when not otherwise currently engaged in active use of a wireless carrier.
FIG. 7 shows relevant conventional system elements between a Home Location Register (HLR), a system Intelligent Roaming Database (IRDB), and a wireless network including a mobile device receiving updated copies of the system IRDB.
In particular, as shown in FIG. 7, a wireless system includes a plurality of mobile devices 830-832, an HLR 820, and a system IRDB manager 802. The system IRDB manager 802 maintains a common system IRDB 810, which is transmitted to all of the mobile devices 830-832 when updated.
FIG. 8 shows the relevant conventional system elements shown in FIG. 7 in more detail.
In particular, the common system IRDB 810 is transmitted to all mobile devices within the relevant wireless network using conventional IS-41 messaging, in particular, using an IS-41 Short Message Service Delivery Point-To-Point (SMSDPP) message. Appropriate switching transfer points (STPs) 900 within a signaling system number 7 (SS7) may be utilized.
Initially, a system IRDB including a selection of wireless carriers to be used was originally installed in a mobile device when purchased by a particular user. However, newer IRDB mechanisms allow for initial installation of a common IRDB when the mobile is initially activated over the air. Later updates of the common system IRDB can be performed whenever the mobile is powered up and available on the wireless network.
When any mobile device powers up, it scans for available wireless carriers, then compares available wireless carriers that it finds to the list of wireless carriers in its system IRDB. Based upon the match and priorities assigned to each matching wireless carrier, a wireless carrier is selected for service by the mobile device.
The common system IRDB includes wireless carrier codes for wireless carriers available to that mobile device as it roams throughout the entire country.
Wireless carrier codes are typically prioritized, e.g., into four main categories. For instance, a wireless carrier may be categorized as being HOME, PREFERRED, NEUTRAL or FORBIDDEN.
There may be only HOME wireless carrier (but not necessarily), a number of PREFERRED and NEUTRAL carriers, and even some FORBIDDEN wireless carriers.
PREFERRED wireless carriers may be, e.g., partners or secondary service providers in other regions and/or states who have agreed to favorable rates with the servicing wireless carrier.
NEUTRAL wireless carriers may include most wireless carriers throughout the country so as to provide the mobile device with a large area of coverage.
FORBIDDEN wireless carriers may relate, e.g., to non-preferred or out-of-plan wireless carriers whom the service provider for one reason or another will not allow its mobile devices to utilize. As another example, a wireless carrier may identify various wireless carriers as FORBIDDEN if a mobile device has a specific calling plan in a home market only, without no roaming authorized, and the wireless carrier doesn""t want roaming charges. Thus, in this example, the system IRDB can be set up so that all other wireless carriers are FORBIDDEN for its mobile devices.
An IRDB has about a 166 byte maximum length, although a wireless carrier list of any length is within the scope of the present invention. Moreover, the current IRDB is limited to holding the codes for a maximum of about 82 wireless carriers, though a wireless carrier list having any plurality of wireless carriers is within the scope of the present invention. Moreover, the actual sizes of the wireless carrier list may vary from format to format. To provide the most complete use of roaming possible, a service provider will utilize large lists of roaming partner wireless carriers typically filling to capacity the system IRDB transmitted to all mobile devices.
FIG. 9 shows an exemplary geographical area serviced by a number of carriers over various geographical areas of the country.
In particular, as shown in FIG. 9, a first geographical region 1010 includes service provided by, e.g., two wireless carriers 1 and 2. A second geographical region 1020 includes service provided by three wireless carriers 1, 2 and 3. A third geographical region 1030 includes service provided by five wireless carriers 3, 4, 5, 6 and 7, and a fourth geographical region 1040 includes wireless service provided by a single wireless carrier 1.
For any given location of a mobile device, only a limited number of wireless carriers 1-7 are available for use by that mobile device within a region surrounding the mobile device. For instance, if a service provider for a particular mobile device is wireless carrier 1, service will be provided in the first, second and fourth geographical regions 1010, 1020 and 1040, while another wireless carrier must be used when the mobile device roams to the third geographical region 1030. The particular wireless carrier 3-7 utilized by the mobile device (including those wireless carriers not matching any entry in the system IRDB in the mobile device) relates to the priority assigned to wireless carriers 3-7 within the system IRDB maintained in the mobile device.
Thus, current IRDB update mechanisms send a common system IRDB containing information regarding all possible roaming partners to every mobile handset that is currently in the wireless network. This updating function, often requiring downloads to millions of mobile devices for any single update, can place a large burden on the network infrastructure of a wireless system.
Accordingly, there is a need for apparatus and methods for updating carrier information in a roaming mobile device which is less burdensome on a wireless network than conventional apparatus and methods.
In accordance with the principles of the present invention, a carrier list database manager for a mobile device comprises a plurality of different carrier lists. Each of the plurality of carrier lists is usable by a mobile device based upon a particular criteria. A carrier code list manager selects one of the plurality of different carrier lists for use by a particular mobile device.
A method of updating a carrier code list in a mobile device in accordance with another aspect of the present invention comprises determining if a mobile device containing a first carrier code list has roamed. If the mobile device has roamed, a second regional carrier code list different from the first carrier code list is downloaded to the mobile device.
A method of updating a carrier code list in a mobile device in accordance with yet another aspect of the present invention comprises determining if a mobile device containing a first carrier code list has changed location based on a registration notification message. If the mobile device has changed location, a second regional carrier code list different from the first carrier code list is downloaded to the mobile device.